Intermittent system for treatment of coal



Feb. 19 192 4. 1,484,256

J. T. FENTON INTERMI'I'TENT SYSTEM FOR TREATMENT OF COAL Filed Aug. 24. 1922 *Normal. Steam s -per-heai-d. Steam Thermo afoul ateni Feb. l@, 124.

JAMES 'I'. BENTON, OF SALT LAKE CITY, UTAH.

INTERMITTENT SYSTEM FOR TREATMENT OF COAL.

Application filed August 24, 1922. Serial No. 584,038.

To all whom it may concern.

Be it known that I, JAMES T. FENToN, a citizen of the United States, and resident of Salt Lake City, in the county of Salt Lake and State of Utah, have invented certain new and useful Improvements in an Intermittent System for Treatment of Goal, of

which the following is a specification.-

The object of this invention is an apparatus for the treatment'of coal by which certain of the volatile substances are distilled off and condensed, gas is roduced, and the treated coal is a type of long flame coke which may be termed synthetlc anthracite or smokeless coal.

This distillation is carried out at a com-v paratively low temperature not exceeding 1200 F. and may be termed non-combustive distillation as there is nocombustion of the coal. The resultant product is a fuel that will burn substantially without smoke and is more valuable than the ordinary coke.

At the same time certain volatile constituents are carried off and condensed separately, providing motor spirits, ammonia for fertilizers, and numerous other valuable by products.

In the present system which is intermittent, thereare provided two retorts which are operated alternately. One retort is filled and the coal therein treated. When the operation is completed, the product is drawn off, and while this is being done, and the retort again filled, the other retort contains coal undergoing treatment. It is calledan'intermittent system because the retorts are operated alternately, although so far as production is concerned there is a continuous operation.

The distillation is carried out entirely by the use of steamwhich is superheated to atemperature of ab0ut1000 F. and forced under pressure through the mass of coal in the retort. The steam and products of distillation are drawn out and pass throu h successive condensers where certain of t e products are condense Advantage is taken of the princi 1e of adiabatic expansion, and by varying t e size of the pipes toeach successive condenser the temperature and ressure are both decreased. For examp e, if the products leaving the retort have a tem perature of 800 F. and a pressure of 20 pounds, by the time they reach the last ex;

pension stage, they will have a temperature of approximately 362? F. and a pressure of 5 pounds.

It will be understood that in. accordance with almost universal practice the various pipes and condensers will vent the loss of heat to the atmosphere so that the temperature and pressure changes will takepla-ce in accordance with said principle. In order to simplify the showing this insulation has not been illustrated.

While other inert heated gases may be used instead of steam, it is found that] the latter is preferable for many reasonsl It not only produces the various volatiles and brings about a certain amount. of'cracking but also carries over the produced volatile matter in a state of suspension. 'When it enters the condenser system it retains the fractional products in suspension until the cooling of the absorption medium allows them to precipitate, thus separating each fraction in such a state of purity that it needs practically no purification. Furthermore, the steam when condensed rovides a the gases an provides medium for washin the medium. for g spirits from the condensers. bined water and motor rawing oflt the motor If the comspirits are passed througha centrifugal pumpythe "water willperform the purpose of washing the spirits. 35

The'steam therefore performs a number of important functions without the assistance of any other medium.

The retorts are provided with means for preheating the same by the means of waste gases from the furnace, andv these waste ases are caused to preheat the retort that is being discharged and again charged and thus help to build up the primary temperature and save the superheated steam besides e5 reventingany condensation of steam. lifeans are provided whereby the flow of waste gases may be directed around either retort as desired by a simple means. An

additional heating device is provided which is governed thermostatically in order that the retorts may be subjected to asubstantially uniform external tem erature.

The external heat applie .to the retorts is merely for preheating purposes and in itpart of the distlllation I self performs no which is performe heated steam.

The above and other objects of my invention will be apparent entirely by the super-.

be jacketed to pre- 60 from the followi'zg no projecting detailed description and the appended claims.

In t e drawing:

The gure is a diagrammatic view of the apparatus employed, only one retort being illustrated.

Referring to the drawing a retort 1 is shown, preferably built up of sections 2, 3, 4, 5 and 6 suitably fastened together. The section 3 may be repeated as desired according to the size of the retort. The section 4 has flanges that rest on supports 7, while the section 2 is provided with a closure 8 for the intake opening. This closure maybe of any desired type so long as it provides an air tight closure. Attached to the upper part of the section 2 is a small section 9 to which are connected certain pipes hereinafter described.

The section 5 is preferably and is provided cumferential enlargement forming a steam passageway 10 whichopens into the retort through. a slot 11. A barring vent 12 is also provided which may be closed in any desired manner. The lower section 6 has a closure 13 hinged thereto at 14 and having at its opposite side fastening means 15 by which-the closure may be held tightly closed. Pivoted at 17 to the closure is a plate 16 upon which the charge of coal may rest and which can swing relatively to the closure when the latter is swung open, so that the product of the treatment may be readily dumped. Any desired form of carrier may be employed to take away the charge after its removal from the retort, either screw or scraper conveyors, or any other suitable mechanism.-

Communicating with the steam passageway 10 is a pipe 18 to which is connected the normal steam line 19 controlled by a valve 21 and the superheated steam line 20 controlled by a valve 22. Communicating with the section 9 is a pipe 23 leading to the atmosphere and also connecting to an auxiliary vapor pipe 26. This pipe is provided with valves 24 and 25, the former controlling communication with the air and the latter controlling communication with the auxiliary vapor line 26. Also connected to the extension 9 is the main vapor pipe 27 controlled by a valve 28.

The main vapor pipe communicates with successive separators 29, 30 and 31, and finally With.the condenser header 32. The sections of this vapor pipe are of gradually increasing size as shown at 33, 34, and 35. As set forth above the purpose of this is to make use of the principle of adiabatic expansion and by allowing the vapors toexpand permit the temperature and pressure to be reduced proportionally. For example if thepipe sections from exit of retort to the header vary in area in about the ratio 9, 15, 28 and 38, it will result that vapors leaving bowl shaped at its lower part with a cirthe retort at a temperature of 800 and 20' pounds pressurewill have a temperature of 362 and a pressure of 5 pounds when they reach the condenser header. This permits automatic separation of the products of distillation in the separators and gives distillates that require but little purification, if any.

While these ratios are found to give excellent results, it is to be understood that they are not fixed, and that the sizes of the pipes may be varied as desired according to the exact purpose which it is desired to attain. In some cases it may be found that pipes of the same size are preferable, or even the later sections might be smaller than the first. The pipe supplying superheated steam to the retort is preferably larger than the outlet pipe, although this relation is not essential.

The auxiliary vapor pipe 26 has branches that communicate with the sections 34, 35 and the condenser header 32'which branches are controlled by valves 36, 37 and 38 respectively. The normal steam line 19 has a branch 39 communicating with the main vapor line and controlled by a valve 40, while the superheated steam line has a branch 41 communicating with the main vapor line at the point shown and controlled by a valve 42. A thermostat 43 located at the entrance of the auxiliary vapor line 26 to the condenser 32 controls both of the valves 40 and 42'. If these valves are both normally closed and the temperature at the condenser header 32tbecomes too low. the thermostat opens the valve 42 and permits superheated steam to pass into the main vapor line. On the contrary if the temperature is too high, the thermostat will open the valve 40 and permit a supply of normal steam to the main vapor line, thus lowering the temperature.

From the condenser header the gases pass through a condenser coil 44 in a water filled container 45, said coil being provided with a drain pipe 46. From the coil a pipe 47 fitted with a back pressure valve 48 leads the gas to the washers or to any further treatment that it may need. 7

Each separator is provided with a plate 49 dividing the passageway into two parts and roviding a. baflle against which the incoming vapors impinge and around which they must pass. This facilitates condensation of the difi'erentfraction's.

Each separator has valve controlled communication 50 with a float controlled valve trap 51 in which there must be at all times a sealing level of. spirits. Since the whole system is under pressure, the outlet of spirits must be controllediby some means which will maintain a seal and allow only sufficient liquid to leave the system unaffected by pressure or anything except the level of the liqnid itself. ably be provided with a valved drain pipe '1 ,aaac y a pressure relief valve 61 and communicating with the storage tank 54. The main line 59 is provided at its end with a spray Jet 62 which forces the liquids in a fine spray into the superheated steam line near its connection to the retort. This secondary cracking system is only brought into operation when the retort has been raised to full working temperature and the secondary treatment causes a very considerable cracking or breaking up of the molecular structures of the oils to form more spirits of the motor spirit type and more rich gas.

If desiredthe separator 29 may be disconnected from this secondary cracking system and the spirits produced in thisstage may be used for. fuel purposes under the boilers and superheater's, since there is no I particular need for further, cracking of this fraction. Also, if desired the secondary cracking system may be dispensed with entirely, and the liquids from the various separators can be led into suitable receptacles for whatever further treatment or use may be'found desirable.

The operation of the device as thus far described is as follows. The retort is filled with coal to the working level and then closed. The valves 24 and are open and the normal steam line valve 21 is opened to permit the steam to drive out the air that may be present in the coal and also slightly preheat the coal. Then the superheated steam valve 22 is slightly opened and shortly thereafter the air valve 24 is closed. The valve 38 is now opened so that the steam and any possible gas and spirits may blow through into the header. As the temperature rises and reaches the point of the third expansion stage, the valve 38 isclosed and the valve 37 opened. Similarly, after a further increase in temperature the valve 37 is closed and the valve 36 opened. Now the normal steam line is closed and the main steam line valve fully opened, allowing the temperature to reach the true working .temperature, and at the same time the valve 25 is closed and the main vapor line valve 28 is opened? The superheated steam with all of the vapors and products of distillation now pass through the three expansive stages and. 'thr ugh the three separa ars 30 and}. 1.,

with an increase in volume and consequent decrease in temperature and pressure as exstat 43 is placed in the condenser header at the point where the line controlled by the;

valve 38 enters, and this thermostat con- .trols the valves 40 and 42 in the normal and superheated steam lines to regulate the temperature as explained above. In this manner, the end boiling point, of whatever spirit it is desired to collect through the water cooled condenser system may be determined.

It is to be remembered that although the system is referred to as intermittent, this retort, since a plu-.

refers merely to each rality of retorts will be used, each having a main pipe 27 controlled by a valve 28 and an auxiliary pipe 26-controlled by a valve 25. All pipes 26 will be connected and all pipes 27 will be connected. It therefore follows that when one retort is in full opera- .plained previously. Preferably a thermotion and heated to its highest temperature,

another retort will be supplying vapor to the header 32 at a lower temperature. For

this reason the thermostat in the header 32 is very necessary, as it enables the temperature to be kept substantially uniform notwithstanding the changing-temperature in 1the vapors from the main and auxiliary Ines. I

Furthermore, ifit were not for the auxiliary line, the first distillate. which comes.

off at a relatively l'OW temperature, Would be condensed at'29 because this separator would not yet be at the final working temperature. distillate directly to the header 32 and regulating the temperature of "this I header through the thermostat, it is possible to separate the desired fractions accurately; notwithstanding the fact that the difl'erent retorts are at difi'erent stages ofthe operation at the same time.

The gases after leaving the water cooled condenser can be made to pass through another separator (not shown) if desired, such as those shown, any oil or water particles contained therein. Atter this, the gas passes through the relief valve, and is treated in any usual or desired fashion to fitit for use. By treatment with cold water the ammonium may be absorbed and extracted.

The liquids leaving the separators pass into the storage tank and are ultimately sprayed into the main or superheated steam line as above explained. A further cracky leading this portion of the I for the purpose of removing ing and the extraction of a greater percentage of distillates results. When the'run of reduced to about 450 when the bottom tit? door is opened and the coal allowed to drop out, whereupon it may be conveyed away by worm or belt conveyors or in any other desired manner. This temperature of 450 F. is below the temperature of spontaneous combustion, and it is desirable to keep the retort at a fairly high temperature it possible. Furthermore a small amount of normal steam shouldbe kept blowing through the retort, and both top and bottom doors should not be open at the same time.

It is believed that the invention will be perfectly clear from the foregoing description. However, the apparatus shown and described is to be considered as illustrative and not as limiting the invention. Parts of the device may be used without others, and various changes in size, form and proportion may be made without departing in any degree from the spirit of the invention. In general it may be stated that the invention is to be regarded as limited only by the scope of the appended claims.

I claim as my invention:

1. Apparatus for the distillation of coal comprising a retort, means for supplying superheated steam thereto, a main vapor pipe leading therefrom, an auxiliary vapor pipe also leading therefrom, a series of separators connected to the main vapor pipe, branches from the auxiliary vapor pipe to certain of said separators, and means for controlling the flow of vapor to the separators through either the main or auxiliary pipes.

2. Apparatus for the distillation of coal comprising a retort, means for supplying superheated steam thereto, a main vapor pipe leading therefrom, an auxiliary vapor pipe also leading therefrom, a series of separators and a condenser header connected, to the main vapor pipe, branches from the auxiliary supply pipe to certain of said separators and to the condenser header, and means for controlling the flow of vapor throu h either of said. pipes.

3. pparatus for the distillation of coal comprising a retort, a steam pipe connected therewith, a normal steam line and a superheated steam line both connected to said steam'pipe, a valve controlled outlet to the air from the retort, a series of separators, two lines of connections from the retort to the separators and means for controlling the vapor flow therethrough as desired.

4:. Apparatus for the distillation of coal comprising a retort, a steam pipe connected therewith, a normal steam'line and a superheated steam line both connected to the steam pipe, a series of separators and a condenser header, two lines of connections from the retort to the separators and condenser header, and means for controlling the vapor flow therethrough as desired.

5. Apparatus for thedlstillation of coal comprising a retort,

inseam means for supplying superheated steam thereto, an outlet vapor pipe, a series of separators connected at intervals to said outlet pipe, and an auxiliary outlet pipe also connected to-certain of said separators.

6. Apparatus for comprising a closed retort, means for'supplying superheated steam under pressure to said retort, a main vapor pipe leading there-' from, a series of separators connected to said pipe at intervals, and an auxiliary vapor pipe leading from the retort and connected to certain of said separators.

7. Apparatus for the distillation of coal comprising a closed retort, means for supplying superheated steam under pressure to said retort, a series of separators, a main vapor pipe leading from the retort to said separators in sequence, an auxiliary vapor pipe leading from the retort and communicating by valved connections with certain of the separators, and means for maintaining a uniform temperature in the last separator.

8. Apparatus for the distillation of coal comprising a closed retort, means for supplying superheated steam under pressure thereto, a series of separators and a condenser header, a main vapor pipe leading from the retort to the separators and condenser header in sequence, an auxiliary vapor pipe leading from the retort to the header and communicating by valved connections with certain of the separators, a double acting thermostat in said condenser header, and means whereby the thermostat maintains a uniform temperature in the last separator.

9. Apparatus for the'distillation of coal comprising a closed retort, means. for supplying superheated steam under pressure thereto, a series of separators and a condenser header, a main vapor pipe connected to said separators and condenser header in se quence, an auxiliary vapor pipe connected to certain of said separators and condenser header, [a superheated steam line and, a normal steam line supplying steam to the retort, a thermostat at the condenser header,

and means whereby the thermostatwontrols the admission of normal or superheated steam .to the main vapor line.

the distillation of coal ill) 10.. Apparatus for the distillation ot coal comprising a closed retort, means for supplying superheated steam under pressure thereto, a series of separators, a main vapor pipe leading from the retort and connecting the separators, the, separators and pipe being larger as the distance from the retort increases whereby the consequent decrease in pressure produces a relative decrease in temperature, and an auxiliary vapor pipe leading from the retort to the separators.

11. Apparatus for the distillation of coal comprising a closed retort, mea for sup plying superheated steam under pressure thereto, a main vapor pipe line leading therefrom, a series of separators of progressively increasing size located in said pipe line, and an auxiliary vapor pipe line also connected to certain of said separators.

12. In an apparatus for the distillation of coal which comprises a retort and a series of separators, an auxiliary cracking system .WhlCh comprises means for conducting the storage condensate from each separator to a tank, a pump for pumping the condensate from the storage tank to a pressure tank, and means'for leading the condensate in the form of a spray back into-the retort.

13. In an apparatus for the distillation of coal in a retort by superheated steam supplied through a steam line which also comprises a series of separators, an auxiliary cracking system which comprises means for conducting the condensate from the separators to a storage tank, and means for forcing the condensate from the storage tank into the steam line in the form of a spray. I

14. In an apparatus for the distillation of coal in a retort by superheated steam Supplied through a superheated steam line which also comprises a series of, se arators, an auxiliary crackin system wh1ch comprises means for con noting the condensate from the separators into a storage tank, a pump for forcing the condensate from the storage tank into a pressure tank, and means for returning the condensate in the form of spray into the superheated steam line, near its point of connection to the retort;

15. Apparatus for the distillation of coal comprising a retort, a superheated steam line for supplying steam thereto, a pipe for conducting the vapors to a series of separators, means for conducting the condensate to a storage tank, and means for forcin the 0011-;

e super- 17. Apparatus for the distillation of coal.

comprising a closed retort, means for supplying superheated steam under pressure to the retort, means for leading off the va ore and condensing the same, means for lea mg away the gases remaining after the vapors have been condensed, and means fors raying the condensate into the superheate steam line and thence into the retort.

In testimony whereof, I have hereunto subscribed my name.

JAMES T. FENTON. 

